1. Field of the Invention
The present invention relates to an X-ray analysis apparatus in which X-rays emitted from an X-ray source are applied to a sample and a semiconductor X-ray detecting means detects the X-rays diffracted by the sample.
2. Description of the Related Art
In general, X-ray analysis apparatuses have an X-ray generating unit and an X-ray detector. The X-ray generating unit applies an X-ray to a sample. The X-ray detector detects the X-ray that is emerging from the sample. In the X-ray analysis apparatus, the sample diffracts an X-ray applied to it at a specific angle. The X-ray diffracted emerges from the sample. The X-ray, thus diffracted, is detected by the X-ray detector.
Various types of X-ray detectors are known, such as zero-dimensional X-ray detector, one-dimensional X-ray detector, and two-dimensional X-ray detector. These X-ray detectors are also known as zero-dimensional counter, one-dimensional counter and two-dimensional counter, respectively.
The zero-dimensional X-ray detector is an X-ray detector that is configured to detect X-rays as points. Examples of zero-dimensional X-ray detectors, known in the art, are PC (Proportional Counter) and SC (Scintillation Counter).
The one-dimensional X-ray detector is an X-ray detector that is configured to detect X-rays as lines. Examples of one-dimensional X-ray detectors, known in the art, are PSPC (Position Sensitive Proportional Counter) and one-dimensional CCD (Charge-Coupled Device) sensor. The PSPC has a linear signal line which generates an electric signal at the position where an X-ray is applied. The CCD sensor has a plurality of CCD elements arranged in a row.
The two-dimensional X-ray detector is an X-ray detector that is configured to detect X-rays in a plane. Examples of two-dimensional X-ray detectors, known in the art, are those known as imaging plate and two-dimensional CCD sensor. The imaging plate is a detector plate that has an X-ray receiving surface coated with storage phosphor. The two-dimensional CCD sensor has a plurality of CCD elements arranged in rows and columns.
The CCD sensor described above is one of semiconductor position sensors. In recent years, various X-ray analysis apparatuses have been proposed, each comprising a semiconductor position sensor. Such an X-ray analysis apparatus is disclosed in Japanese Patent Laid-Open Publication No. 2002-250705, pp. 4–6, FIG. 2. It is expected that X-ray analysis apparatuses of this type analyze X-rays faster than the zero-dimensional counter and the one-dimensional counter.
In the conventional X-ray analysis apparatus that has a two-dimensional CCD sensor, X-rays are detected while the sample (i.e., object of analysis) and the two-dimensional CCD sensor are moving relative to each other. The apparatus can hardly detect X-rays at high speed or high sensitivity. This is because the CCD pixels cannot receive X-rays at high resolution when the sample and the two-dimensional CCD sensor move relative to each other at an excessively high speed.